That is a good question! :-)
I thought that when fighting cold sorcs (that use mastery and therefore lower your resist) it is recommended to stack res (like +300) so after the -100 hell + -1xx cold mastery your remain with positive resistance.
But what happens when fighting a fire sorc as an Amazon?
Example:
I have 210 fire res while wearing hotspurs so in Hell it gives me 90 Fire res on display. But actually I have 20 res on top (after subtracting -100 from hell)
Now comes a Fire Sorc that has 3*5/5 (weapon+CoA) Fire Facets = -15 Resistance.
So how much damage is dealt?
A) Damage dealt based on 90-15 = 75 Resistance = 25% Damage

Damage dealt based on 110-15 = 95 Resistance but 90 is max on display = only 10% Damage
This post was edited by xxTheDudexx on Nov 12 2021 04:37am